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Title:
ARRANGEMENT IN UNDERGROUND MINING MACHINE, AND METHOD
Document Type and Number:
WIPO Patent Application WO/2020/115035
Kind Code:
A1
Abstract:
An arrangement and method of underground mobile mining machine (M) for cable reeling. The arrangement comprises a reel (1), and hydraulic components, comprising: a hydraulic motor (5) connected to and for rotating the reel, a tension control valve manifold (4) configured to control tension of the cable, a pump (8) hydraulically coupled to the hydraulic motor (5) by a reeling-in line (26) and a reeling out line (27), the pump arranged to control pressure fluid flow and direction, a control device (10) arranged to control displacement and the pumping direction of the pump (8), a pump proportional valve (11) arranged to control displacement and delivery of the pump (8), and connected to the control device (10), a first throttle (22) arranged between the pump proportional valve (11) and the control device (10), a second throttle (23) connected to the control device (10). The hydraulic components establishes a closed hydraulic system, and the pump (8) is connected to a system (33) configured to generate a braking moment counteracting a moment caused by a cable (25) unwinding from the reel (1).

Inventors:
HAIKIO SAMI (FI)
AHO HEIKKI (FI)
Application Number:
EP2019/083479
Publication Date:
June 11, 2020
Filing Date:
December 03, 2019
Export Citation:
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Assignee:
SANDVIK MINING & CONSTRUCTION OY (FI)
International Classes:
B60L9/00; B60T1/10; B65H54/00; B66D1/50; E21C33/00; E21F13/02; E21F17/06; H02G11/02
Domestic Patent References:
WO1997028592A11997-08-07
WO2016138565A12016-09-09
WO1984002430A11984-06-21
Foreign References:
US2759684A1956-08-21
US5419508A1995-05-30
US4114827A1978-09-19
EP2937467A12015-10-28
GB613542A1948-11-30
US3334839A1967-08-08
CN106167233B2018-07-31
GB2158031A1985-11-06
US2639103A1953-05-19
US3250492A1966-05-10
GB1003141A1965-09-02
GB2021507A1979-12-05
EP2810809A12014-12-10
US5007599A1991-04-16
Attorney, Agent or Firm:
SANDVIK ASSOCIATION (FI)
Download PDF:
Claims:
CLAIMS

1. An arrangement of underground mobile mining machine (M) for cable reeling, the arrangement comprising

- a reel (1), and hydraulic components, comprising:

- a hydraulic motor (5) connected to and for rotating the reel ,

- a tension control valve manifold (4) configured to con trol tension of the cable,

- a pump (8) hydraulically coupled to the hydraulic motor (5) by a reeling-in line (26) and a reeling-out line (27), the pump arranged to control pressure fluid flow and di rection,

- a control device (10) arranged to control displacement and the pumping direction of the pump (8),

- a pump proportional valve (11) arranged to control dis placement and delivery of the pump (8), and connected to the control device (10),

- a first throttle (22) arranged between the pump propor tional valve (11) and the control device (10),

- a second throttle (23) connected to the control device

(10) ,

- the hydraulic components establishing a closed hydraulic system, and wherein

- the pump (8) being connected to a system (33) configured to generate a braking moment counteracting a moment caused by a cable (25) unwinding from the reel (1) .

2. The arrangement as claimed in claim 1, wherein the un derground mobile mining machine (M) is an electrically driven machine and the cable (25) is an electric cable ar ranged for supplying electrical energy for use of said mining machine (M) .

3. The arrangement as claimed in claim 1, wherein the ca- ble (25) is a hose for supplying fluid (s) and stored on a reel .

4. The arrangement as claimed in any of the preceding claims, comprising a second pump proportional valve (12), arranged to control displacement and delivery of the pump (8), and connected to the control device (10) .

5. The arrangement as claimed in any of the preceding claims, wherein the control device (10) comprises a con trol piston,

- the pump proportional valve (11) being connected to a first chamber of the control piston,

- the first throttle (22) arranged between the pump pro portional valve (11) and the first chamber of the control piston (10), and

- the second throttle (23) being connected to a second chamber, opposite to the first chamber, of the control piston .

6. A method for cable reeling of an electrically driven underground mining machine, in which method the cable (25) is wound by rotating a reel (1) in a first direction by a hydraulic motor (5) coupled thereto, the hydraulic motor (5) being pressurized by a pump (8), and unwound from the reel (1) by allowing the reel (1) to rotate in an opposite direction in a braked condition by using the hydraulic mo tor (5) as a hydraulic pump, the method comprising

- during unwinding, generating hydraulic pressure to pres sure fluid in the hydraulic motor (5) ,

- receiving said pressurized pressure fluid in the pump (8) for driving the pump (8),

- operating by the pump (8) a system (33) configured to generate a braking moment, and

- converting said hydraulic pressure into electric, me chanical and/or pressure fluid energy in said system (33) .

7. The method as claimed in claim 6, wherein during un winding of the cable (25) , the method comprises - returning pressure fluid used for driving the pump (8) back from the pump (8) to the hydraulic motor (5) .

8. The method as claimed in claim 6 or 7, wherein during winding the cable (25) on the reel (1), the method com prises

- first driving the pump (8) at its maximum delivery,

- when the desired tension level of the cable (25) is achieved, limiting the delivery of the pump, and

- maintaining equilibrium between said delivery and said tension .

9. The method as claimed in any of claims 6 - 8, compris ing

-shifting the controlling of the reel (1) in a service stage, and

- controlling the speed of the reel (1) in said service stage by pump proportional valves (11, 12) .

Description:
ARRANGEMENT IN UNDERGROUND MINING MACHINE, AND METHOD

BACKGROUND

The invention relates to an arrangement of underground mo bile mining machine for cable reeling.

The invention further relates to a method for cable reel ing of an electrically driven underground mining machine.

In electrically driven underground mining machines, con trolling cable reeling, i.e. winding and unwinding of a cable extending from the machine to a power source has an important role.

Traditionally the cable reeling in underground mining ma chines is realized by an open or half-open hydraulic cir cuit systems. In these systems, the reel speed cannot be directly controlled. The reel speed is a result of the tension control. Certain conditions are problematic, for example beginning of driving and reversal of driving di rection, as well as sudden acceleration of the machine. In these situations, mechanical friction and inertia of the reel may disrupt the control.

It is also known applications using mechanical feedback from machine motion in controlling cable reeling. In these applications an exact controlling may be difficult as the cable speed is linked to the transmission of the machine. For example, if the wheels are slipping, the cable speed is not matched to the ground speed of the machine but it is matched to the speed of the slipping wheels. This will either cause over-tensioning of the cable, or pay out loose cable depending of driving direction. Inaccuracy of the tension control causes unnecessary elon gation and wear in the cable, which reduces the lifetime of the expensive cable.

The poor controllability of the reel may also cause a whip-lash effect when a loose cable is tensioned. Typical ly, this happens when the reeling system is activated and the loose cable is reeled in before driving begins. Whip lash effect will cause a risk of the cable hitting person nel near the cable. Cable hitting tunnel walls and possi ble nearby equipment may damage the cable. The whip-lash happens when the reel initially is stationary. Torque needed for starting the reeling is higher than in running condition. A rather high pressure level is needed to start the rotation of the reel. Then the torque and friction condition improves when rotation starts, resulting unde sired rotational acceleration of the reel. This leads to the uncontrolled whip-lash.

BRIEF DESCRIPTION

Viewed from a first aspect, there can be provided an ar rangement of underground mobile mining machine for cable reeling, the arrangement comprising a reel, and hydraulic components, comprising: a hydraulic motor connected to and for rotating the reel, a tension control valve manifold configured to control tension of the cable, a pump hydrau lically coupled to the hydraulic motor by a reeling-in line and a reeling-out line, the pump arranged to control pressure fluid flow and direction, a control device ar ranged to control displacement and the pumping direction of the pump, a pump proportional valve arranged to control displacement and delivery of the pump, and connected to the control device, a first throttle arranged between the pump proportional valve and the control device, a second throttle connected to the control device, the hydraulic components establishing a closed hydraulic system, and wherein the pump being connected to a system configured to generate a braking moment counteracting a moment caused by a cable unwinding from the reel.

Thereby an arrangement providing at least one of the next advantages may be achieved: precise controllability, avoiding the whip-lash effect, possibility to unwind the reel without tensioning the cable, low energy consumption, and a compact structure of the arrangement.

Viewed from a further aspect, there can be provided a method for cable reeling of an electrically driven under ground mining machine, in which method the cable is wound by rotating a reel in a first direction by a hydraulic mo tor coupled thereto, the hydraulic motor being pressurized by a pump, and unwound from the reel by allowing the reel to rotate in an opposite direction in a braked condition by using the hydraulic motor as a hydraulic pump, the method comprising

- during unwinding, generating hydraulic pressure to pres sure fluid in the hydraulic motor,

- receiving said pressurized pressure fluid in the pump for driving the pump

- operating by the pump a system configured to generate a braking moment, and

- converting said hydraulic pressure into electric, me chanical and/or pressure fluid energy in said system.

Thereby a method providing at least one of the next ad vantages may be achieved: precise controllability, avoid ing the whip-lash effect, possibility to free cable un winding from the reel, and low energy consumption.

The arrangement and the method are characterised by what is stated in the independent claims. Some other embodi ments are characterised by what is stated in the other claims. Inventive embodiments are also disclosed in the specification and drawings of this patent application. The inventive content of the patent application may also be defined in other ways than defined in the following claims. The inventive content may also be formed of sever al separate inventions, especially if the invention is ex amined in the light of expressed or implicit sub-tasks or in view of obtained benefits or benefit groups. Some of the definitions contained in the following claims may then be unnecessary in view of the separate inventive ideas. Features of the different embodiments of the invention may, within the scope of the basic inventive idea, be ap plied to other embodiments.

Same control principles are possible to use in other reel ing solutions in mobile mining machinery, for example hos es stored on a reel and arranged for supplying fluid (s), such as air, water etc.

The hydraulic circuit of the arrangement is basically a hydrostatic closed loop circuit. In the circuit, the flow and direction of fluid is controlled by adjusting control piston of the pump. An electrical pump controller with a mechanical or electric feed-back linkage of the pump wash- plate angle may be used. In some embodiments, there is no feed-back linkage at all. A further valve system is added to the pump control for creating a tension control. The tension control valve system creates a control pressure which is used to adjust the pump control piston angle. The adjustment has a range from maximum positive to maximum negative, providing means to reverse the flow direction of pressure fluid.

This valve system overrides the speed-control when a de sired cable tension is met. The tension control valves are preferably electro-proportional ones that make it possible to fine-tune the tension with the driving conditions of the machine.

A braking moment is created when the cable is pulled out from the reel by the machine travelling away from the ca ble anchoring point. The braking moment is created with the pump operating as a hydraulic motor and a system for generating braking moment and driven by the pump. The sys tem for generating braking moment may comprise, for in stance, an electric generator or mechanical transmission capable of recovering the braking energy. In an embodi ment, the electric motor operating the pump is also ar ranged to operate as a generator for recovering the brak ing energy.

During normal driving of the machine, the pump controller (speed control) is set to a maximum inwards reel speed. The tension control will then override the speed control when the cable tension level is achieved. Equilibrium be tween the speed and tension control is found and this sets the correct speed of the reel. During reversal of the ma chine travelling direction, the control pressure from ten sion control valves forces the pump to reverse the pres sure medium flow to maintain the mentioned equilibrium.

The pressure level may be adjusted by driving conditions of the machine, such as speed, acceleration etc. Further more, the diameter of the reel changes as the amount of cable on the reel is changing. The compensation may be re alized by varying the pressure level of the system to maintain constant tension in the cable.

During acceleration and deceleration of the machine the rotational inertia of the reel is compensated by varying the pressure level. The torque generated by the reel motor is directly proportional to the system pressure differen tial over the motor.

The arrangement and method may have a very precise speed control which is insensitive to variations in the pressure and motor torque. This may require a feed-back from a pump control device. This feature may be used during service of the arrangement, e.g. when the cable is changed. The cable reel may be rotated with precise speed control in both di rections without starting torque and starting friction levels affecting to the control. This is achieved by con trolling pump proportional valves with e.g. a joystick and setting the cable tension to a very high but still safe level .

BRIEF DESCRIPTION OF FIGURES

Some embodiments illustrating the present disclosure are described in more detail in the attached drawings, in which

Figure 1 is a schematic view of an arrangement and method for controlling cable reeling.

In the figure, some embodiments are shown simplified for the sake of clarity. Similar parts are marked with the same reference numbers in the figures.

DETAILED DESCRIPTION

Figure 1 is a schematic view of an arrangement and method for controlling cable reeling of an underground mobile mining machine M.

The underground mobile mining machine M may be any type of a mining vehicle or a construction vehicle. In mines and at other work sites different type of vehicles are used. The vehicles may be provided with one or more working de vices for executing designed work tasks at the work site. The vehicle may be a wheel loader, a transport vehicle or dumper, a rock drilling rig, an excavator or a lifting ma chine, for example.

The underground mobile mining machine M is an electrically driven machine that comprises at least one electric motor 35 that is connected by an electric cable 25 to a source of electric power (not shown) .

The arrangement 100 for controlling reeling of said cable 25 comprises a reel 1 in which the cable is attached, and hydraulic components.

A rotational axis 36 of the reel 1 is arranged horizontal ly. Horizontal axis allows the cable enter the reel in wider angles, even from front of the machine.

However, in another embodiments, the rotational axis 36 may be vertically arranged. Vertically arranged axis typi cally demands a storage drum and a spooling system.

A hydraulic motor 5 is connected to and for rotating the reel 1 in a winding and an unwinding directions.

A tension control valve manifold 4 is configured to con trol tension of the cable 25 and keep the tension in pre determined range of tension values and reel is released with valve 20 if needed.

A pump 8 is hydraulically coupled to the hydraulic motor 5 for driving the same by a reeling in line 26 and a reeling out line 27. The pump 8 is arranged to create pressure fluid flow in the hydraulic motor 5. The pump is driven by a drive unit 24, such as an electric motor. In an embodi ment, the electric motor 35 is arranged to operate as the drive unit 24. A control device 10, such as a control piston or a control vane, is arranged to control displacement and the pumping direction of the pump 8. In the embodiment shown in Figure 1, the control device 10 is a control piston. A pump pro portional valve 11 is connected to a first chamber of the control piston for controlling through the control piston displacement and thus the delivery of the pump 8. In an embodiment, the arrangement may also comprise a sec ond pump proportional valve 12, arranged parallel with the (first) pump proportional valve 11 and connected to the control device 10. In the embodiment shown in Figure 1, the second pump proportional valve 12 is connected to a second chamber of the control piston.

A first throttle 22 may be arranged between the pump pro portional valve 11 and the first chamber of the control piston. In embodiments comprising the second pump propor- tional valve 12, a second throttle 23 may connected be tween the second pump proportional valve 12 and a second chamber, opposite to the first chamber, of the control piston . In an embodiment, the pump 8, the control device 10, the proportional valve (s) 11, 12, and the throttle (s) 22, 23 are arranged in a single element 3 that may be called as a pump assemb1y . The hydraulic components establish a closed hydraulic sys tem. The pump 8 is connected to a system 33 configured to generate a braking moment counteracting a moment caused by a cable 25 unwinding form the reel 1. In an embodiment, the system 33 is realized by the drive unit 24 that com- prises an electric motor, which is able to function as an electric generator. In another embodiment, the system 33 comprises a separate electric generator for converting the braking energy into electric energy. In still another em bodiment, the system 33 comprises a transmission for con verting the braking energy into mechanical or pressure fluid energy. Thus the system 33 may convert the braking energy to usable form of energy, not wasting it all as heat .

In the embodiment shown in Figure, the tension control valve manifold 4 comprises a tension control valve 18 con nected to the reeling-in line 26. A third throttle 28 is arranged between the tension control valve 18 and the reeling-in line 26. The tension control valve 18 is moni toring and limiting pressure in the reeling-in line 26. Said pressure is proportional to the tension of the cable 25. Thus the tension control valve 18 limits the maximum cable tension in a predetermined tension value.

The tension control valve manifold 4 may also comprise one or more pressure measuring device (s), such as a first pressure measuring device 29 adapted to measure pressure in the reeling-in line 26, and a second pressure measuring device 30 adapted to measure pressure in a reeling-out line 27.

In another embodiment, the pressure measuring devices 29, 30 have means 31 for creating electrical signal propor tional to the respective pressure, and an electrical transmitter. The pump proportional valve 11 is an electri cally controlled valve and electrically connected to at least one of said first and second pressure measuring de vices 29, 30. In this embodiment, the tension control valve 18 may be excluded.

According to an aspect, the arrangement may comprise a length monitoring means 32 configured to monitor the amount of the cable 25 on the reel. The length monitoring means 32 is configured to create a length information, such as an electrical signal, based on the amount of the cable 25 on the reel. Based on the length information, a control unit 34 of the arrangement is adapted to vary the pressure level of the hydraulic motor 5.

According to an aspect, in the method the cable 25 is wound on the reel 1 by rotating the reel 1 in a first di rection by the hydraulic motor 5 coupled thereto. The hy draulic motor 5 is run by the pump 8.

When the cable 25 is unwound from the reel 1, the reel 1 is allowed to rotate in an opposite direction, not freely but in a braked condition. During unwinding, the hydraulic motor 5 acts as a hydraulic pump that generates hydraulic pressure to pressure fluid in the hydraulic motor 5. Said pressurized pressure fluid drives the pump 8 that operates a system 33 configured to generate the braking moment for constraining the rotation of the reel 1 and tensioning the cable 25. The system converts the hydraulic pressure into electric, mechanical and/or pressure fluid energy.

In an embodiment of the method, during unwinding of the cable 25, the pressure fluid used for driving the pump 8 is returned back from the pump 8 to the hydraulic motor 5.

In an embodiment of the method, during winding the cable 25 on the reel 1, it is first driven the pump 8 at its maximum flow for motor to provide the high speed to reel. Following the desired tension level of the cable 25 being achieved, the delivery of the pump 8 is limited and con trolled such that equilibrium between said delivery and said tension is achieved and maintained. According to an aspect, the arrangement may have at least two operational stages: normal operational stage for wind ing and unwinding the cable 25 during mining operations of the underground mobile mining machine M, and a service stage. In the service stage, the cable reel 1 may be rot ted in a controlled manner and directly controlled by the operator during service operations.

In an embodiment, the controlling of the speed of the reel 1 in the service stage is realized by pump proportional valve (s) 11, 12 that is/are controlled through e.g. a joy stick (not shown) .

In an embodiment, a flushing spool 6 and a flushing relief 7 are included in the arrangement for selecting a low- pressure side of working circuit (reeling lines 26, 27) for flushing. The flushing spool 6 and the flushing relief

7 may be arranged together with the hydraulic motor 5 in a single motor assembly 2.

In an embodiment, the arrangement comprises a booster pump 9 that is used for generating a pilot pressure and filling the hydrostatic circuit.

The arrangement may comprise a boost pressure relief valve 13 for setting the pressure level of boost and low pres sure side of the hydrostatic circuit.

In an embodiment, the arrangement comprises pressure cut off valves 14, 15 arranged to limit maximum working pres sure by forcing the control piston 10 towards middle point thereof, and thus towards smaller displacement in the pump

8.

The arrangement preferably comprises high-pressure relief valves 16, 17 that are protecting the arrangement against sudden over-pressurization in case of system overload or malfunction of cut-off valve 14, 15.

A control pressure relief valve 19 may be used for limit- ing maximum control pressure.

In an embodiment, the arrangement comprises a free circu lation valve 20 that makes it possible to release the reel 1 to be freely rotated.

The arrangement preferably comprises a filter 21 config ured to filter pressure fluid circuiting in the arrange ment . The invention is not limited solely to the embodiments de scribed above, but instead many variations are possible within the scope of the inventive concept defined by the claims below. Within the scope of the inventive concept the attributes of different embodiments and applications can be used in conjunction with or replace the attributes of another embodiment or application.

The drawings and the related description are only intended to illustrate the idea of the invention. The invention may vary in detail within the scope of the inventive idea de fined in the following claims.

REFERENCE SYMBOLS

1 reel

2 motor assembly

3 pump assembly

4 tension control valve manifold

5 hydraulic motor

6 flushing spool

7 flushing relief

8 pump

9 booster pump

10 control device

11 pump proportional valve

12 second pump proportional valve

13 boost pressure relief valve

14 pressure cut-off valve

15 pilot relief valve

16 high-pressure relief valve

17 high-pressure relief valve

18 tension control valve

19 control pressure relief valve

20 free circulation valve

21 filter

22 first throttle

23 second throttle

24 drive unit

25 cable

26 reeling-in line

27 reeling-out line

28 third throttle

29 first pressure measuring device

30 second pressure measuring device

31 means for creating electrical signal

32 length monitoring means

33 system for generating braking moment

34 control unit 35 electric motor

36 reel axle

100 arrangement

M underground mobile mining machine




 
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